Cobalt ferrite, Copper ferrite and cobalt doped copper ferrite nanoparticles have been synthesized and characterized using different characterization methods (XRD, FTIR and FESEM). The prepared nanoparticles have been used as promising fillers of the polyvinylidene fluoride (PVDF) polymer. The PVDF/(Cu-CoFe2O4, CoFe2O4, and CuFe2O4) nanocomposites films have been prepared via a simple solution casting technique. The optical properties and the piezoelectric response of the prepared nanocomposite films have been studied. The study showed that Cu-CoFe2O4, CoFe2O4, and CuFe2O4 have enhanced the interfacial polarization density and dielectric constant. The optical conductivity value of PVDF/ (Cu-CoFe2O4 and CoFe2O4) increased five times compared with the pure PVDF. Also, an increase in the piezoelectric response has been recorded by adding the nano-fillers to the pure PVDF.